Radiator for cooling fluids



'.3 Sheets-Sheet 2 s. W. RUSHMORE RADIATOR FOR COOLINGl FLUIDS FiledDec, 6,'1921 may 15,1923.

Patented May l5, i923.

UNHTE@ STATES SAMUEL RADIATOR FOR. COOLING FLUIDS.

Application filed December 6, 1921.

To all 'whom it 'may concern.'

Be it known that I, SAMUEL lV. RUSH- Moina, a citizen of the UnitedStates, and resident of Plainfield, in the county of Union and State otNew Jersey, have invented certain new and useful Improvements inRadiators for Cooling Fluids, of which the following is a specification.

My present. invention relates to radiators, particularly radiators forvuse with cooling systems ot' the type which operate by the boiling` andcondensing cycle for the cooling ot automotive engines, on the principledescribed in my Patent No. 1,378,724, granted May 1T, 1921. ln suchsystems the water and steam f rom the engine jacket is discharged into aseparating'chamber in the bottom ot' the radiator, the water beingreturned to the engine ljacket and the steam risinginto the air-cooledpassages ot the radiator, so that the radiator operates as an up-tlowcondenser, the condensate returning by gravity against the upward flowof steam.

ln said patent this method is referred to as applicable to radiators ofthe types which are non' employed as standard equipment on automobiles`trucks, etc., but such radiators are primarily designed for cooling ofwater instead oi" steam. by down-flow instead of upiow. and l havediscovered that in the practical operation of such radiators by thesteam cooling system, the potential cooling capacity is not fullyutilized.

The primary dilliculty is that the fan which draws the cooling airthrough the radiator. induces a much heavier blast in the centralportions of the condensing area than at the sides. Consequently thecentral portions are capable of radiating much more heat and condensingmuch more steam per unit ot' cooling surface, than are the sides. Butthe side passages which are least cool are designed to have the same. orless, flow resistance than the central portions. with the result thatwhere the relatively frictionless, massless steam is substituted torwater, the balance between the several up and down passages. as regardsflow capacity and condensation capacity, is completely upset.

(laretul experiment shows that long before the total volume of steam tobe condensed becomes great enough to tax the cooling capacity of theradiator as a Whole, the interior cooling capacity at the sides will beover -taxed The heat therefore creeps passages.

W. RUSHMORE, OF PLAINFIELD, NEW JERSEY.

ESSU@ Serial No. 520,210.

higher up, heating the side portions; the air bcomes lighter so that thehot air and steam rise up into the empty space at the top of theradiator displacing the colder air downward (because the Colder air 'isheavier and because air, even at 212 F., is about 60% heavier thansteam) but the same or evenI greater volume of steam flowing directly upinto the better-cooled central portions is condensed long before itreaches the top, the' passages and air above it being kept cold by thefan. The iup-flowing steam can push the air upward only the limitedheight to which such steam rises before being condensed.

As a result there remains in the central portion of the radiator a bodyof air which is supported from below by 11p-flowing steam and sealed inabove by steam rising from the sides. Reverse curl or eddying of suchVsteam from the sides may serve to scav enge out more or less of the airin the relatively open space above the honeycomb, but has practically noeffect on the air trapped and kept cold in the narrow central passagesof the radiator. Hence the air thus trapped stays trapped, pi `ictieallyexcluding the steam which might otherwise flow in from both top andbottom.

While this objectionable action may be more readily analyzed andunderstood in connection with radiators of the ty e in which the steampassages are paralle vertical conduits having no cross flow connectionsexcept at top and bottom, nevertheless, the same action is found tooccur to an undesirable extent in radiators of the type in which thehoneycomb is built up from a multiplicity of short horizontal tubesforming an interconnected net-work of passages and cross-connections.

In its broadest aspects, my invention includes `proportioning andarranging the steam condensing passages with reference to the ditlerentportions ot' the area of the radiator so that the steam will flowthrough all of the condenser passages at rates which will insure drivingthe contained air to a point suitable for its collection and discharge'instead of trapping it.

The preferred point Jfor collection and discharge of the air is theupper space in the radiator above the top of the condensing To drive itthere l arrange matters so that steam will not reach the well cooledcentral portions of the radiator eX- cept from below. There are manyfactors,

.one or more of lwhich may be-varied separately or together to bringabout this result. The up-flow paths at the sides may have their flowcapacity decreased. This may be accomplished by making them longer, orof smaller cross-section, or arranging them so that the flowing steamwill be checked by a succession of high-angled impacts, all of whichfactors are utilized in the device of my prior application, SerialNumber 500,-

382 filed September 13, 1921. The decrease of fiow section and theobstruction by impact may be distributed from bottom to .top of the sidepassages as in said application, or may be localized at desired points.

For radiators of the type in which the radiating elements consists ofvertical tubes arranged to afford separate parallel paths for fiow ofthe steam, a similar result may be accomplished by having anobstruction, preferably at the upper ends of the .s ide tubes, therebyincreasing the How resistance at said upper ends.

The obstruction may be any desired form fof local constriction,preferably a closure with a Vent through it. The vent may be very small,because proper functioning requires onl an extremely small flow capacityat t is point, merely sufiiclent'to permit slow in and out breathing inresponse to variations of height to which t-he steam has to rise in thetubes before itis condensed. A Vent sufficiently large for this purpose,may yet be small enough to afford relatlvely enormous throttlingresistance to outrush of steam in quantities such as would causedown-flow in the central tubes.

Where the tubes are large, say to ,Se inch in internal diameter, it mayprove convenient to have a separate vented closure 1n the upper end ofeach side tube, but, if desired,

a single closure may be fitted over the ends of several adjacent tubes,1n which case a single vent is used for each closure. Thus the Vent-maybe proportionally larger for a given resistance. .Such group arrangementis particularly desirable where the tubes are of such small diameterthat control of each by a separate vent would require a vent so smallthat it would be in danger of getting clogged.

The size of the vent is preferably such that the volume of steamescaping from the tops of the side tubes will be kept well below thecondensing capacity of the top space, until and except when the steamevolution in the base of the radiator becomes great enough to bring thesteam to the tops of the best cooled central tubes.-

The radiating capacity of said space may be increased, as by making thesame a secondary miniature radiator, preferably of the cross-tube type.

I nfay obstruct and vent all of the tubes in the radiator on the generalprinciple `vention as embodied in a radiator of the vertical tube ty e.

Fig. 2 isa pllan view of a horizontal section on the broken line 2-2,Fig. 1.

F 1g. 3 is an enlarged detail in vertical section on the line 3-3, Fig.2.

Fig. 4 is a Vertical sectional elevation showmg a modification.

Fig. 5 is a top plan view in horizontal section on the broken line 5-5,F ic. 4.

F ig. 6 is a vertical sectional detail of a modification taken on alinecorresponding to line 6-6, Fig. 5. p

Fig. 7 is an elevation partly in section, and Fig. 8 a detailed verticalsection showlng anothermodifcation.

It will be understood that the radiators as shown in these drawings areof the air cooled type, and adapted for use in combination withthemotor, water supply system, pump and fan commonly employed onautomotive Vehicles. They may be, and preferably are, units adapted tobe substituted for the radiator 4, in the combination of parts shown inFig. 1 of my abovementioned patent; but they may be employed, withA orwithout modifications. Whereverl an equal-flow up-flow, or airscavenging condenser is desired.

In Fig. 1 of the present drawings, the radiator, here used as acondenser, comprises the separatingchamber l into which the steam or hotwater and steam from the' engine is discharged through pipe` 2. Thewater,vincluding condensate, flows out of said space through pipe 3,preferably drawn by a pump which is preferably a force pump and may be agear pump, as shown in my said patent.

From the separating chamber extend parallel-related tubes, as 4, 4a, 4b,and 4b, communicating at their upper ends with the space 5 at the top ofthe radiator. Assuming that the structure shown is of the full sizecommonly employed on trucks, the tubes 4 maybe, say 24 inches high andin diameter, 4 inch to Vinch, or of much smaller diameter, as on someautomobiles. In practice, there may be many more of them than are shownin the drawings.

Said parallel tubes are secured in thin transverse plates 6, 6, theprimary function lll() eral tubes.

of which is to conduct and radiate heat from the walls of the tubes,although they also ai'ord some protection and lateral support, tendingto hold the tubes in properly spaced relation. The ends of the tubes aresoldered, steam-tight, in perforated bottom plate 7 and top plate 8.There may bean overtlow pipe 13 through which air may breathe 1n andout. There is usually also the iller cap 14:. through which airinevitably enters, when fresh water is supplied to replace losses.

As previously explained, the tubes at the sides are not so well suppliedwith air draft bv the fan and hence are not so well cooled as are thecentral tubes. The normal result of this would be for the steam toexceed the condensing capacity of the side tubes, and rise into spacewhile a similar volume of steam flowing into the central tubes would befully condensed in the lower part thereof. The obstructions for'prevent-ing this are shown in Figs. 1, 2, and 3, as afforded by a plug9 in the upper' end of each tube, each plug being provided with a ventl() of suitable length and diameter. All of the tubes are shown assimilarly plugged and vented on the general principle that the ventsafford no serious obstruction to slow breathing. yet will throttleexcessive outrush ot steam from any tube that may be or become deficientin radiating capacity as compared with other tubes` but I find thatequipping the side tubes only is sufficient, and therefore preferable.

While the sizes of the vents may be graduated to correspond with thecondensing efficiency ol each separate tube, this is not necessar v anda few sizes, or a single. properly selected size, may be used with goodresults.

The tubes heilig all supplied with steam at the same pressure, the sizesof the vents required for the side tubes will depend primarily upon theflow resistances of the sev- Where the tubes are all of the samediameter, as in the present case. the vent must be small enough size orgreat enough length so thatafter the air has been gradually expelledfrom the side tubes, as above described, and live steam begins to flowout ot their tops, the How resistance at the vent will be sufiicient topile up a slight back pressure. Such back pressure necessarily takeseffect as an upward pressure in the central tubes. Such upward pressurefrom the side tubes as 4b must be sufficient for establishing andmaintaining the large volume ot flow of steam which the central tubes,such as 4a, will sustain by reason of its greater' condensing capacityper unit area of cooling surface, and, in addition, the excess pressurenecessary to lift the heavy cool air in the upper parts of a centraltube 4, This air, as we have seen, is a fluid which is naturally someheavier than the steam which is now filling the side tube 4b, and, inthe present case, said air has 20% or so additional Weight because itiskept nearly at atmospheric temperature by the direct blast of the fan,as against the boiling temperature of the live steam in the side tubes,4:.

The greater the condensing capacity of the top space 5, the greater maybe the volume of steam that may be permitted to escape from the sidetubes without material impairment to functioning. Hence I prefer'- ablyprovide the casing of the upper space with heat radiating ribs 11, 11,and if desired, with transverse air tubes 12, 12. A group of these crosstubes 12 is shown as centrally located and Will be recognized asconstituting a miniature condenser of the cross-tube, or honeycomb,type.

I find that locating the restrictions at the tops of the side tubes, hasadvantages over locating them at any other point in the tube, and alsoover making the side tubes of uniform smaller flow-section throughouttheir length. One advantage is that the downlow of condensate is lessretarded by the 11p-flowing steam.

The modifications shown in Figs. 4, 5, and 6 will be readily understoodfrom the above full description of the forms shown in Figs. l, 2', and3. In the modifications, a single closure and vent for each group ofadjacent tubes, instead of for each tube, is provided. This arrangementis particularly adapted for radiators in which the vertical tubes aregreatly multiplied in number and correspondingly reduced in dlameter. Insuch radiators very thin-walled, copper tubes, having a diameter of 9,-inch or less, are commonly employed. \Vhile such tubes couldconveniently be supplied with individual constrictions at their tops` itis evident that a single closure and vent lfor a group ot' tubes will beless expensive to manufacture and the vent may be proportionally largerso that it is less liablev to become clicked with scale. sediment ordirt. The vent needs to be small only in relation to the combined crosssectional areas of all of the tubes of the group and need only be smallenough to limit free {iow of steam from the tops ol the less cooledgroups and to establish the slight back pressure which will force intothe central tubes, the relatively large volume of steam necessary toutilize their superior condensing capacities; and to do so with torcesniiicient to lift and expel the heavy cool air in the central and upperportions of said central tubes.

In Fig. 4, the vertical tubes are comprised in tour groups of which theside groups are controlled by caps 9, 9, having vents 10, 10a; and thecentral groups by caps 9", 9b having vents 10", 10". As before stated,there may be a greater or less number of individual groups and caps and,if desired, only'the side groups need be capped, the central l groupsremaining unobstructed.

' Another feature shown in Fi 4c is having the over-flow pipe 13aarrange with its intake located near the bottom of upper space 5. `Thisarrangement is'of advantage because when steam escapes from the tops ofthe'side tubes in any substantial Volume, andthere begins to be a slightpressure to cause out-flow through 13, the fluid that flows out will bethe downwardly displaced heavyair rather than the steam which nat'-urally seeks the top of said space 5.

It will be noted that the'vents 1'0b do not lead from the lowest pointin space 5; hence space 5 will not be completely drained of condensate.i This may be of no great importance in some climates and under certainconditions, but where complete drainage of condensate is desired, thevents may be arranged after the manner shown in Fig. 6.- Here the groupsare closed in by plate 30, having separate cavities 31, 31, for eachgroup of tubes. The upper surface of the plate is formed as shown sothat all condensate will drain by gravity toward the downwardly directedvent 10X.

In the foregoing I have referred to the tubes which are less cooled andwhich require restriction of their flow capacity as being the sidetubes, and those which are better cooled and more likely to trap air asbeing the central tubes. It will be'evident, however, that in attemptingto apply my invention to radiators other thanl those illustrated herein,it will always be a question of fact for the designer to determine whichtubes of his radiator have excessive flow capacity or deficient cooling.

For instance, la vertical tube radiator may have so many banks of tubesfrom front to rear and these tubes may be so thin walled and closely setthat rear tubes may be insufliciently cooled as compared with the fronttubes. In such case the basic principle of my invention would requirethat the rear tubes have their flow capacity Irestricted as comparedwith front tubes in the same line of draft, in addition to having all ofthe side tubes, whether front or rear, restricted with' referenceI tothe central tubes.

Figs. 7 and 8 indicate a simple arrangement wherein two vented artitionsare employed on the so-called cellular type of radiator. In this type,the up-and-down passages afford separate parallel paths for flow ofsteam and condensate, but each flow path follows vertical and horizontaldirections alternately, as by following three sides` of successiverectangles. These zig zag passages are commonly formed by two sheets ofthin brass or copper of the desired length, folded together and solderedat the edges to form fiat tubular strips, having a cross section, saythree to three and one-half inches from front to rear of the radiator,but in thickness only one-sixteenth inch to onetoward the respectivesides. Such radiators are standard equipment on Crane-Simplexautomobiles.` This radiator, in original form, when connected foroperation in accordance with my steam cooling method,

gave marked indications of the above-de. scrlbed premature rush of steamthrough the,

shorter side passages and a cold spot due to trapping of air at theupper central portions of the honeycomb. 4

This radiator was then equipped with two partitions 19a, 19, one on eachside, shutting off' the outlets of the side tubes which are shorter andfarther removed from the cooling draft produced by the fan. In eachpartition is a vent 10. This arrangement works well when the diameter ofthe vents is, say one-eighth of an inch -to one-sixteenth of an inch, oreven less. When the diameter is one-eighth of an inch and the engine isworking `at full load, there seems to be enough steam from the vents toheat up the space in the top of the reservoir, but the steam comingthrough the vents is insufficient to trap air in the central portion.The central portion heats up clear to the top and all over before anysteam blows off. While advantage may be derived from partitions withone-eighth of an inch, or even more diameter of vent, it is evident thata vent less than one-eighth of an inch in diameter is preferable.

The above-described two-partition arrangement will improve thefunctioning in radiators of the small-diameter, straighttube type wherethe tubes are all of the same length as described in connection withFig. 4, and will prove even more useful where the side tubes are shorterthan the central tubes and are therefore of relatively lowresistance andcorrespondingly great flow the open air may and the atmosphere. ltfollows that in certain cases the open air may be substituted for saidempty space/andthat, if the vents are properly propostioned, they mayhave their pressure cross-commumcation through the open air.' Eitherwith or without said empty space, the vents leading to be controlled byvalves it' desired. F or instance, out-breathing check valves may bearranged for every vent; or in-breathing valves for some vents andoutbreathing valves for others. For instance, in F ig. 4, the twocentral vents 10b, 10", may be provided with out-breathing valvesJ andthe two side vents 10, 10 with in-`\ breathing valves. Preferably, suchvalves will be very light, particularly the outbreathing valves may besmall ball check valves with the ball made of bakelite.

It will be recognized that my present inventions concern ways ofdiverting or shifting the flow of steam to a desired extent from theradiator passages of less cooling capacity to those of greater coolingcapacity. As concerns the broad invention the arrangements herein shownare. closely related to` those of my applications, Serial Numbers500,381 and 500,382, led September 13, 1921, and Serial Number 520,209,filedDeccmber 6, 1921. The present case is selected for presentation ofthe generic claims, the intention being to present in the otherapplications claims which cannot be made 1n this application.

I claim:

1. A radiator embodying separate interior passages for up-low of steamorvapor to be condensed; means including a cross communication between.the lower portion of said passages for up-flow supply of steam or vaporto said passages, some of the flow paths normally having greater coolingcapacity than others; portions of the flow section which have lesscondensing capacity being arranged to have less flow capacity than thosehaving greater condensing capacity.

2. A radiator comprising a lower chamber and an upper chamber andseparate intermediate passages cross-communicating through said lowerand upper chambers; means for supplying steam in said lower chamber andwithdrawing condensate therefrom and means whereby air may breathein andout of said upper chamber to relieve eX- cessive internal pressure andvacuum conditions attendant upon use of the device, the passages of lesscondensing capacity having greater flow resistance than those of greatercondensing capacity.

3. A radiator comprising a lower chamber and an upper chamber and amultiplicity of separate intermediate passages cross-communicating onlythrough said lower and upper chambers; means for supplying steam in saidlower chamber and withdrawing condensate therefrom and means forpermitting air to breathe in and out of said upper chamber in responseto the internal pressure changes attendant upon use of the device,certain of said passages being of similar flow section but less lengththan others in combination with means for obstructing out-How of steamfrom said shorter passages.

4. A radiator of the type comprising a lower chamber and an upperchamber and a multiplicity of separate intermediate passagescross-communicating only through said lower and upper chambers; meansfor supplying steam in said lower space and withdrawing condensatetherefrom land means for permitting air to breathe in and out of saldupper space in response to the internal pressure changes attendant uponuse of the device, certain of said passages being of similar flowsection but of less length than others in combination with ventedoutlets for said shorter passages to permit slow in and out breathing ofair While throttling outrush of steam from said shorter passages whentheir radiating capacity is overtaxed.

5. A variable-duty, air-cooled radiator of the type comprising a lowerspace connected by a multiplicity of upwardly extending tubes with anupper space; means for discharging boiling liquid or steam into saidlower space and for withdrawing condensate therefrom; and a desirednumber of re.- strictions controlling outlet of steam from the upperends of a desired number of said tubes.

6. A variable-duty, air-cooled radiator of the type comprising a lowerchamber connected by many upwardly extending tubes with an upper spacefor escape of air; means for discharging boiling liquid or steam into 1said lower space and for withdrawing condensate therefrom; and a desirednumber of vented outlets each controlling outlet of steam from the upperend of a different group of tubes.

7 A variable-duty, air-cooled radiator of the type comprising a lowercross-connection communicating with many upwardly eX- tending tubes;means for discharging boiling liquid or steam into said lowercross-connection and for withdrawing condensate therefrom; and a desirednumber of vented outlets, each controlling outlet of steam or vapor fromthe upper end of a different group of tubes, the tubes being grouped forsimilarity of condensing capacities.

8. A variable-duty, air-cooled radiator of the type comprising a lowerspace connected by a multiplicity of upwardly extending tubes with anupper space accessible to air; means for discharging boiling liquid orsteam into said lower space and for withdrawing condensate therefrom;and one or more vented outlets, each controlling outlet of steam orvapor from the upper ends of a group of tubes having lesser condensingcapacity.

9. A radiator in which the interior paths for flow of steam or vapor tobe cooled are laterally distributed and some of the flow paths normallyhave greater cooling capaclty than others, and are arranged to permitescape of air through the upper portions thereof, in combination withconnectionsl for operating said radiator as an up-ow condenser; portionsof the flow section havlng less condensing capacity being arranged tohave less flow than those having greater condensing capacity.

10. A variable-duty, air-cooled radiator in which the interior paths forflow of fluid to be cooled are laterally distributed and some of theflow paths normally have greater cooling capacity than others and arearranged to permit escape of air through the upper portions thereof, incombination with means for 11p-flow supply of steam or vapor to interiorpaths of different cooling capacilties simultaneously and4 atapproximately equal pressures;- selected portions of the fiow section oflesser condensing capacities being arranged to have correspondinglygreater flow resistance whereby other portions having greater condensingcapacities are adequately supplied with steam or vapor beforesaid'first-mentioned portions are overtaxed enough to permit excessivethrough-How of the steam or vapor. v

11. An air-cooled radiator in which the interior paths for flow of fluidto be cooled are laterally distributed and some of the flow paths haveless cooling capacity per unit length than others; and means forsupplying said fluid thereto from a common source simultaneously and atapproximately the same pressures; portions of the flow section havingless cooling capacity being arranged to have correspondingly greaterflow resistance than those having greater cooling papacity; for thepurpose and with the result that the fluid automatically distributes itsflow according to the several cooling capacities. 12. A variable-dutyradiator having many interior paths of different cooling capacities orrates; means lfor up-low supply of steam or vapor to many of saidinterior paths simultaneously at approximately equal pressures, wherebyair within the radiator is automatically forced by the flow of the steamor vapor to a region determined by the volume 'of said flow, by theseveral flow capacities and condensing capacities of the severalpassages, and by the superior weight of the air; in combination withflow restricting means for limiting the free flow of steam from the lessactively cooled passages into said re on,

13. variable-duty, air-cooled radiator of a type having many interiorpaths of different cooling capacities or rates; means for up-flow supplyof steam 0r vapor to many of said interior paths simultaneously,whereby, as the volume of steam increases, air within the radiator isautomatically forced by the flow of the steam or vapor to a regiondetermined by the volume of said flow, by the several flow capacitiesand condensing capacities of the several passages, and by the superiorweight of the air; in combination with an outlet from said regionpermitting inand out-breathing of air, and flow restrict-- ing means forlimiting the free flow of steam from the less actively cooled passagesinto said region.

14. A variable-duty radiator of the motor vehicle ntype which is ofrelatively large front area and thin from front to rear and adapted tobe cooled by an induced draft effective unequally on different portionsof the front area; said radiator comprisinga lower chamber and an upperchamber connected by many upwardly extending tubes of similar material,crosssection and thickness of walls, cross-communicating only throughsaid lower and upper chambers; means for supplying boiling liquid, steamor vapor to all of said tubes simultaneously and at approximately thesame pressures through said lower chamber and for withdrawing condensatetherefrom; and flow restricting means for imposing predeterminedrestriction on flow of steam or vapor from the upper ends of certain ofthe tubes which are less effectively cooled than from others' for thepurpose described.

15. In the combination specified by claim 14, the further feature thatthe less wellcooled tubes are shorter than other tubes and the ventstherefor are correspondingly restricted to prevent up-rush of steam orvapor in excess of the radiating capacity of the upper chamber.

16. An air-cooled condensing apparatus affording interior, laterallydistributed, parallel paths for flow of fluid to be cooled, some ofwhich parallel paths have less cooling capacity than others; and meansfor supplying said fluid to the parallel paths from a common source;certain of the parallel flow paths of less cooling capacity beingarranged to have substantially greater total fl'ow resistance than thosehaving greater cooling capacity; for the purpose and with the resultthat the Huid automatically flows in greater quantity to the flow pathshaving greater cooling capacity,

17. An air cooled radiator having low resistance How paths for thecooling fluid over the central portions of comb and higher flowresistance for the paths at the slde portions of said area.

Signed at New York in the county of New York and State of New York this5th day of December, A. l). 1921.

SAMUEL W. RUSURE.

the area of the honey-

